The present invention relates to a cutter for use in civil engineering and construction works and, more particularly, to a cutter having disc-type blades for cutting concrete, brick, tile, or the like, in civil engineering and construction works.
In a conventional cutter for cutting a Hume concrete pipe, a concrete secondary product, bricks, tiles, asphalt or the like in civil engineering and construction works, a disc-type blade having diamond tips in its periphery is rotated by an electric motor. In order to ensure the safety of the cutting operation, the disc-type blade is partially covered with a safety cover, and the blade is secured directly to a rotary shaft of the electric motor or to a transverse rotary shaft of a speed reduction mechanism which is connected to the rotary shaft of the electric motor.
Accordingly, in the actual cutting operation, such a safety cover for the blade or such a rotary or transverse rotary shaft to which the blade is secured, restricts the blade cutting concrete or the like to a certain depth and hence the cutting blade can not enter entirely into concrete or the like while cutting the same. For example, the blade can be buried only up to 1/3 of its diameter into concrete. In other words, when a concrete plate is cut, a blade having a diameter three times as long as the thickness of the concrete plate must be used.
As a result, there is much needless expenditure of both material (and thus, of course, increased manufacturing costs) for such a conventional cutter, since the blade or cutter can be buried up to only a proportion of its diameter. Further, use of the conventional cutter results in excessive cutting of concrete or the like and, finally, it is inconvenient to transfer or transport the conventional cutter. In addition, when the cutting operation is carried out in a narrow working space, operational efficiency is lowered, and the danger of the cutting operation is increased.